Glycerol / Glycerine


Experience From - Matt Mahoney, Karl King, Brent Backus, Torin Dewey , Ed Furtaw, Kevin Ash, Doug Clark, Jay Hodde , Rob Robergs , Joe Galope , Ron Jansen , Herb Hedgecock , Rich Schick ,

Matt Mahoney

This question was asked:

Does anybody have any information or opinions concerning the use of glycerin as an energy source.

Glycerine or glycerol is taken before a hot weather event to increase water retention, delaying dehydration. I have not used it. I understand the benefit is marginal and you have to take a whole lot of it. Taking too much can make you sick, though not seriously so, since it is a natural component of fat.

Karl King

It is not an effective energy source for running, but has been used to increase the body's ability to stay hydrated in hot running conditions. Dr. David Martin has published on its use in marathoning. He is an advisor to Steve Spence, who supposedly was to use this during the Olympic marathon in Barcelona. There is evidence that the method works, but there can also be some unpleasant side effects. It would take some practice to establish what is an effective dose for a given runner.

At present, use of glycerin is not against USOC rules. However, considering that one needs to take it in fairly large amounts, far beyond what is ever found naturally in the body, and it is not a nutrient per se, I question the ethical use of it. Since it can have some bad side effects, my advice would be to forget about it unless you are running for a medal in the Olympics. Rather than try to find some magic bullet, study what constitutes good nutrition during training and racing, and apply that.

Brent Backus

I have used glycerin to super-hydrate myself prior to my long runs in hot weather. Recent studies by the U.S. Army and the Univ. of Mexico have clearly demonstrated the benefits of glycerol for athletic performance. The studies have shown increases in endurance to exhaustion of 22% to 32% when glycerol is used to prehydrate before exercise. Individuals with diabetes, hypertension, or any other serious medical problems should consult with their Doctor before experimenting with glycerin. For more information on how to prehydrate and beat the "heat" please contact Brent Backus 509.255.5018 or

Torin Dewey

Person wrote:

So, I went to the store, and got the largest bottle, 118ml for $3. Now I'm looking at it and wondering if glycerol and glycerine are the same, or just virtually the same, and is it a good idea to put this in the only body I'll ever have, or should we wait a few more years for sports drinks to incorporate this , or ,or ,or...

According to the Merck manual and any chemical supplier, glycerol and glycerine are exactly the same compound, chemical formula:


As for the other questions surrounding its use as preventing against dehydration, I, too, will wait for more studies (and most likely still never try it, relying on other more pleasing beverages).

Ed Furtaw

Dave H. Wrote:

The May/June 1993 issue of "On The Roads" included an article "Coping with Dehydration using Glycerol Infusion". It recommended a 26.5/1 ratio of water to glycerol, using 0.8 milliliters (ml) glycerol per kilogram of body weight ( thus for me about 150 pounds-68 kilograms about 54 ml of glycerol in 1430ml of water), and ingest this over the couple hours preceding a run. I won't try to cover all the article here. Suffice to say it referred back to the April 1990 issue of Medicine and Sports and its report of a glycerol study. The general idea is that you become better and more thoroughly hydrated.


An article also appeared about that time in "Running and Fitness News", a publication of the American Running and Fitness Association. It reviewed the 1990 study and its favorable results. But it concluded " Before you dash off to the drug store, be aware that in other experiments some participants have experienced headaches. Wait for additional studies to demonstrate how useful glycerol can be and how it should be used." So I put that in file.


So, I went to the store, and got the largest bottle, 118ml for $3. Now I'm looking at it and wondering if glycerol and glycerine are the same, or just virtually the same, and is it a good idea to put this in the only body I'll ever have, or should we wait a few more years for sports drinks to incorporate this , or ,or ,or...

Here's a note of caution on the prospective use of glycerol by runners as an aid in hydration. I am currently reading a book entitled "Environmental Neurotoxicology" published by the National Research Council (1992). Among other things, the book contains a "Partial List of Neurotoxicants" (Table 1-1). GLYCEROL IS INCLUDED IN THIS LIST OF NEUROTOXICANTS! I have not found any specific discussion of how or why it is neurotoxic. But please be warned, and use that stuff (and all chemicals) with caution if at all.

Kevin Ash

I received this issue of Running and Fitness News and finally decided to try it after reading the article. Walgreens carried it as "glycerine", sold in 4 oz bottles for $2.89. I added this to a 96 oz bottle and filled the rest with water and Cytomax. That was close to the recommendations above.

I wanted to try it before using it as my primary beverage on my long run this weekend so yesterday I drank about 12 oz before a hard nine mile run. Temperatures were in the mid 80's so it was fairly warm. My heart rate was lower than I would have expected, and I had a very good run considering my workouts the previous 4 days. I certainly can't say for sure whether it helped or not - I wanted to make sure it didn't have any adverse side affects which would ruin my long run tomorrow.

I had no problems with it, so I will try it on my long run. Tomorrow I'm going to do 36 miles of hilly trails; temps are supposed to be 85-90 so it should be a good test. I will post afterwards and let you know how it went.

It went like this:

I drank a 28oz bottle of the glycerine/cytomax/water mixture 90 minutes before running and then I used it during the first half of my run as my replacement drink. It did not go well.

What I noticed was:

I actually felt so bad that I didn't finish my run.

So in conclusion, I will not be using it again and would NOT recommend using glycerine in you energy drink.

Doug Clark

I just bought my first box of 24 pouches of "Glycerate HydroOptimizer" for less than $30. Each pouch holds about 2 tablespoons of a clear, almost odorless, sweet tasting fluid. The pouch says "Ingredient: Glycerine USP 99.5% (Glycerol)". Note the singular form of the word ingredient.

According to the package, the recipe for my 185 pound body is 4 pouches mixed with a little less than 2 liters of water. Start drinking this soon enough to finish it before your run (60 to 90 minutes ? ).

At noon Friday, I mixed 1 pouch with 2 cups of water before my 6 miles. I wanted to see if my body would complain about glycerol. It did not.

I plan to use it full strength this Sunday for my long run - will report.

Jay Hodde

I have no experience in using glycerol for ultra endurance, but I found the following message posted to the sport science mail list interesting and informative. I'm reposting it to IUS-L for those interested. The rest of the thread can be obtained by pointing your browser to : and clicking on "forum".

Rob Robergs

I have read the postings on the glycerol issue with interest, and need to inform you of several facts.

  1. I am one of the University of New Mexico scientists who first researched glycerol hyper hydration for improved exercise performance. Based on our and Bud Riedesel's findings (1987), the university invested in patent protection for using glycerol as a hyper hydration agent suitable for use during exercise. In 1996, the patent was purchased by InterNutria, a nutritional supplements company within the larger InterNueron Pharmaceutical Company. Thus, InterNutria has patent protection for using glycerol hyper hydration for enhancing exercise performance.

  2. I am currently contracted by InterNutria to provide scientific advice and commentary on their glycerol product - "ProHydrator". ProHydrator was scheduled to be released to market this June, but the USOC ban on glycerol 'came out of the blue' and has delayed the product release. Such a delay was decided by the company due to the sponsorship of USA Triathlon, as well as several professional triathletes.

  3. From my understanding, the USOC ban is based on glycerol being classified as a tissue dehydrator. Other tissue dehydrators are mannitol, sorbitol, and urea. Such substances are routinely used in clinical practice to dehydrate the brain and eye as a treatment for edemas resulting from a variety of clinical disorders. It just so happens that mannitol, sorbitol, and urea are also potent osmotic diuretics. Glycerol seems to have been included in the banned list of mannitol and sorbitol due to the potential for glycerol-induced diuresis.

  4. I have recently written a major review of the clinical and applied uses of glycerol ingestion. It is currently in review. Within this manuscript is a section that pertains to glycerol-induced diuresis. It is important to remember that glycerol ingestion is not the same as glycerol hyper hydration. The latter involves the additional ingestion of 1-2 L of water. Simply ingesting a concentrated solution of glycerol will not hyper hydrate the body, but dramatically increase glycerol concentrations in the blood, interstitial fluid, and kidney filtrate. Increased urinary glycerol has the potential to increase urine flow due to retarding water reabsorption in the kidney. This is the mechanism of the diuresis from mannitol and sorbitol.

    Glycerol does not cause a marked diuresis, however, because glycerol is still rapidly reabsorbed in the proximal and distal tubules. Mannitol and sorbitol are not. There is no evidence in the medical literature for a glycerol-induced diuresis. Nevertheless, anecdotal expressions of glycerol-induced diuresis occur in many manuscripts.

    I have written a scientific reply to InterNutria for use in the company petitioning the USOC to remove the ban on glycerol.

  5. It is ironic that glycerol has been used by the world's elite athletes for many years. Although it is easy to assay for urinary glycerol, and interpret data, I do not think the testing lab has or is currently performing the assay. It would be easy to detect exaggerated use of glycerol as the kidney can reabsorb almost all glycerol up to blood glycerol concentrations approximating 1.2 mmol/L. As resting blood glycerol approximates 0.05 mmol/L and may increase to 0.5 mmol/L during extreme prolonged exercise and carbohydrate depletion, the only way to cause glycerol to appear in the urine is to ingest large quantities. Thus, if the USOC wanted to, they could easily determine a urinary concentration indicating large amounts of glycerol ingestion. For your information, urinary glycerol can increase to above 20 mmol/L within 30 min after ingesting 1.2 g glycerol/kg body wt.

  6. The USOC is not justified in the ban on glycerol for hyper hydration or proposed metabolic advantages to athletes. Hyper hydration is no worse than ingesting liquid carbohydrate or water during exercise. In addition, glycerol turnover data indicate that 60% of glycerol is converted to glucose in the liver and kidney, 30% is incorporated into glycolysis for oxidation, and the remainder is presumably involved in triacylglycerol metabolism.

    It appears that the ban on glycerol is a mistake and should be reversed in the near future. Failure to reverse the ban will not only expose to elite athletes to continued high risks of heat injury, but potentially result in a series of law suits from athletes and nutritional companies against the USOC.

    I hope these facts help you understand the glycerol saga !

Rob Robergs, Ph.D.
Director: The Center For Exercise and Applied Human Physiology
The University of New Mexico

Joe Galope

Someone on the list inquired about Glycerol on the list. I asked the same question a couple of months ago and got this post by Bill Misner. He said:

"Glycerol turns over to 60% glucose conversion(gluconeogenesis) in liver/kidney, 30% goes to glycolysis for oxidation, while the token 10% remainder goes to triacylglycerol metabolism. Stanko et al(1993) used 100 grams DHA to 25 grams pyruvate for enhancing muscle glucose extraction during prolonged muscle exercise approximately 20%, and somewhat less effective using only DHA. Intake of 125 grams DHAP(Although optimal levels could also be achieved on 5 grams intake) significantly increased muscle glycogen stores in this study.

Marvin Riedesel (1980, MEDICINE AND SCIENCE IN SPORTS, April) showed that Glycerol metabolization to DHA metabolizes to glucose and increased byproduct water-volume either for storage, urination, tissue fluid stores, or skin cooling.

Yes, it would appear that DHA from fatty acid metabolization is a gluconeogenetic action (6 parts in 10), while 3 parts are receptive to glycolysis. Personally I suspect phosphorylation the main reason for DHA's lessor ergogenic effect when absent from its pyruvate associate. Somewhere down the line, glucose, for effectual-maximum-efficient energy, needs the phosphorylation process, I.E. ADP-ATP:Substrate-O2-NAD-Ubiquinone-Cytochrome c-& O2 in mitochondrial cells.

One cycling Athlete told me that he could go farther using Glycerol-Loading for Hyper hydration and energy metabolism. Several world class athletes have used it for years in order to tissue-load more fluids in order to combat heat stress injuries in ultra events held in the heat of summer. Glycerol is currently a banned USOC substance if used as a diuretic, or if an athlete is tested "positive". It is safe for use as directed in a 3 gram dose with 16-20 ounces of water 90 minutes before endurance runs, and will create some tissue water-storage, not diuresis as some have suggested. I hope this is of some help, you can always post me back if you want to go deeper.

Ron Jansen

Thanks to all who responded on and off the list regarding glycerol. Bottom line is that there is a lot of disagreement over the potential benefits versus harmful effects of the stuff. Guess I'll stick with more traditional measures for staying hydrated.

Seems that I should have done a bit of surfing prior to posting the question, though....found some information later. If you're interested, check out:

Herb Hedgecock

Jay Anderson wrote:

"I am confused about the difference between the many variations in the names Glycerol, Glycerin, Glycerine, Glycerates, etc. I have had people tell me that all of the above names are chemically identical (they are the same thing). I find it confusing then that the USP grade Glycerine that I have says to call your local poison control center if ingested. What is that all about?"

Glycerol, glycerin, and glycerine are all identical. Part of the reason for the different names is simply that chemical nomenclature developed over the centuries, by different groups of people, and different names are recognized by different groups. It's no big deal to us chemists who know where to go look to see what the names really mean. If you are really interested in learning something about some chemical substance, then there are plenty of places to go look - one of the simplest is the "Merck Index."

Also, if you are interested in the hazards of some substance, then you can look at the MSDS sheet for that substance to learn something about its hazards. (MSDS = material safety data sheet). There are many Internet addresses to MSDS info, one I like is

If you look up glycerol, then you will note that it is not toxic. One of the reasons that bottles are labeled with harsh warnings about toxicity is the usual "CYA" mentality to cover lawsuits. By The Way: all chemical substances are toxic at some level, even water.

Moving on, the glycerate is not glycerol. That term could refer to several substances related to glycerol, but in any sort of proper use of chemical nomenclature, glycerate is not glycerol.

Rich Schick

Spent a little time researching this one. The topic has been drifting around the literature for 7 or 8 years. The studies have had mixed results. Some show that the glycerol helps others that it makes no difference. From what I could make out there seems to be problems with the control solution. It would be important that the total volume of fluids taken with and without the glycerol would be identical, and that the total sodium, glucose, etc., would also be identical. This was not well done in the studies I saw.

I guess the bottom line is that it doesn't seem to do any harm other than a bloated feeling reported by some test subject and it might do some good -- but I wouldn't bank on it.

I found the article below which points out potential problems specific to ultra running. I also found out that glycerol was a banned substance for a short period of time back in 96, but a successful effort was launched in protest and it is now "legal" in competition.

Even though it does not appear to be helpful, I am concerned that in ultra-distance races glycerol may potentially be harmful. I suggest this because of the increased anti-diuretic hormone (ADH) levels that were observed. Elevated ADH is one proposed mechanism behind the hyponatremia that is observed in athletes towards the end of an ultra-distance race. Also note the increased incidence of gastrointestinal complaints in the glycerol group. Certainly something to be avoided during a long race.

1. Physiological responses to glycerol ingestion during exercise. Source: Journal of Applied Physiology. 71(1):144-9, 1991 Jul.